‘98 6.5 TD stalled while driving and current no start

[Turbine Doc]

Lift Pumps & OPS operation and troubleshooting

Okay fuel delivery basics for the 6.5 On the 6.5 you have a fairly simple fuel delivery system. Starts at the tank, a suction strainer, to lift pump, to filter manager, to IP shut off solenoid, to IP, flow is controlled to IP via PCM demand to PMD/FSD. Depending on vintage power to the...

www.thetruckstop.us

 

[scurry]

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So completely new here (just got a 96 TD in Jan) been chasing electrical issue in mine. And have discovered that transmission and engine are separately run and only "touch" in two places the PCM ground and the power from Ignition switch. Your original issue was transmission. And you have crank but no fuel at injectors. So a bad ignition switch can supply power for starter and LP but not supply power to PMD (through PCM power and ground) and Transmission. So would have fuel up to IP but no or bad signal from PMD due to low or "bad" power so wont send fuel to injectors as would have no timing info. This would also give codes you are getting on cranking. This would have you looking at the location that would effect both transmission and crank no start. You said you found bad grounding at PCM strap which could cause failure in ignition switch due to amp draw to overcome "bad" grounding. (Also did you check fuses? ECM, FUEL SOL, IGN A/B) you can look for battery voltage at PCM And PMD (This part is from AI as dont know wires and locations and to lazy to go through wiring diagrams) PCM is C1 or C2 pink or orange wire, Stable >9.6 on crank(should match battery voltage). And PMD pink wire at connector. Stable battery voltage during crank. If >0.5v off of battery voltage, bad ignition is probable. Also said not seeing codes from transmission. This could = no power to transmission module so ignition switch again.

But do try all above suggestions as I've just started to learn these trucks and could be completely off as there is something the above people know that removes ignition switch as possible cause of failure. But I think ignition switch should be considered if come up to a point where might be a LP or PDM replacement as ignition switch is like $50 .

 

[ak diesel driver]

PMD is a possibility just not as high on the list. There is no transmission module, the PCM is both engine and trans

 

[jrsavoie]

I had to replace the ignition switches on every GMT400 except the 1994s and I think, the 1989

Usually around 260,000 miles

 

[ak diesel driver]

Wow must be getting Alzheimer's. I meant to write ignition switch instead of PMD